This invention relates to a new tetracycline antibiotic, 7-chloro-8-methoxytetracycline, isolated from antibiotics designated as antibiotic ES-119 and antibiotic Tet. 7, which are produced by fermentation under controlled conditions using biologically pure cultures of the new microorganisms, Actinomadura brunnea var. antibiotica var. nov. ATCC 53108 and Actinomadura brunnea var. antibiotica ATCC 53180, respectively.
In a related, commonly-assigned, co-pending application which is U.S. Ser. No. 763,740 filed Aug. 8, 1985, now abandoned, filed on even date herewith, another new tetracycline 7-chloro-8-methoxy-2'-N-methyltetracycline, produced by fermentation of A. brunnea ATCC 39216 is disclosed.
In another related, commonly-assigned, co-pending application now U.S. Pat. No. 4,752,605, filed on even date herewith, another new tetracycline, 7-chloro-4a-hydroxy-8-methoxytetracycline, produced by fermentation of Dactylosporangium vescum ATCC 39499 is disclosed.